1. Field of the Invention
This invention relates to contact status detectors, and more particularly to a closure detection circuit for use with relays.
2. Description of the Prior Art
In electrical circuits incorporating a plurality of signal carrying switches, it is often desirable to have a positive indication of the status of the switch, in order to assure that the circuit is in the desired switched configuration. Typically, this need is particularly desirable in circuits employing relays.
In view of this need, prior art systems have been developed to provide some type of relay switch detection capability. However, these prior art systems typically require the use of a separate set of contacts to indicate the particular status of the relay. Furthermore, these prior art systems tend to be unreliable, since the actual relay contacts are not monitored directly.
In addition, prior art systems for use with relays monitor only the primary and secondary contacts of the relay and are generally incapable of providing a signal when the relay is stuck between its two alternate contacts.
Consequently, it is a principal object of the present invention to provide a contact status detection circuit which is capable of directly monitoring switches, in general, and relay contacts, in particular, to determine the status of the contacts.
Another object of the present invention is to provide a contact status detection circuit having the characteristic features described above which is also capable of directly monitoring all relay contact status conditions including when the relay is stuck between its two alternate contacts, and providing a separate and unique output signal for each possible condition.
Other and more specific objects will in part be obvious and will in part appear hereinafter.